Steam-engine.



SLROSENZWEIG.

STEAM ENGINE.

APPLICATION men MAR. I6, m1.

Patented Sept. 11, 1917.

3 SHEETS-SHEET I.

Ni 3mm. m Siegfried HOSEIQLUQ? LL Ma? attorney Patented Sept. 11, 191 7.

3 SHEETS-SHEET 2.

g llll l V s a attor y Siegfried P056215 weig S. ROSENZWEIG.

STEAM ENGINE.

APPLICATION FILED MAR. I6. 1917.

1 ,239,827. Patented Sept. 11, 1917.

3 SHEETS-SHEET 3.

. Ma awi Siegfried fiosenjwel q I 1oniit.ting the steam piston and the devices a I UNITED sTAT s oFFIoE.

srnernrnn nosnlvzwnre, or new YORK, x. Y.

To all whom it may concern:

Be it known that I, SIEGFRIED Rosnxzwnro, residing in New York city, in the county and State of Xew York, have invented a new and useful Improvement in Steam-Engines,v of which the following is a specification.

My invention relates to reciprocating piston steam engines of the uniflow type, having a central main exhaust port or ports in the steam cylinder wall uncovered by the steam piston toward the end of the expansion stroke, and auxiliary exhaust ports and mechanically operated controlling valves therefor, through which steam escapes, after the main exhaust has been closed, with a view to regulate and control the compression.

It is my object to provide a. simple and efficient means of automatically adjusting the auxiliary exhaust valves to thus regulate and control the compression. To this end, operate the auxiliary exhaust valves by means of cams driven'through suitable intermediaries from, and revolving in unison with. the engine crank shaft. and rotatably shiftable relatively thereto'to vary the time of opening of the auxiliary exhaust relatively to that of closing the main exhaust, as described and claimed in my prior application, Seriai No. 135,112. filed December 5th, 1916, on which Letters Patent will issue of even date herewith; and through the intermediary of actuating means whose movements are "controlled by the exhaust pressure. I thus shift said cams automatically. conformably to variations in said exhaust pressure, with a viewto maintaining the compression for which the auxiliary valve gear may be set.

To enable others skilled in the art to make and use my invention. I will now proceed to describe'the manner in which the same is, or may be. carried into effect by ref; erence to the accompanying drawings. forming part of this specification, in which Figure 1 is a side elevation of so "much of a unifiow engine a ceded to explain my invention'the conne of the governor shaft 4: with the "en" .nk shaft beingf diagrammatically ind- M of the steam cylinder g broken away'tg," expose the piston therein;

Fig. 2 is a somewhat'enlargcd cross section. partly in elevation, on 'line 2-2, Fig. I

d. andthe side 1 ha a be '(A being o STEAM-ENGINE.

, specificaftion ot' Letters Patent. Patented 11, Y. Application filed March 16, 1917. Serial No. 155,244. I

for adjusting, whether automatically or otherwise. .the auxiliary exhaust valve operating cams. r Figs. 3, l and 5, are on a larger scale. ,and are designed to exhibit the structural details of the means for adjusting the auxiliary exhaust valve operating cams. Fig. 3 is a vertical axial section, partly in elevation, of the governor shaft and auxiliary exhaust .valve operating cams andlnecllanical means for adjusting the same.

Fig. 4; is a longitudinal section on line Ji -l. Fig. 3, the spiral slots abeing diagrammatically represented as straight.

'Fig. 5 is a cross section on line 55 of Fig. i.

In the drawings, 1 are the bonnets for the tappets on the rock-shaft 2 for operating the two steam inlet valves 10, located at opposite ends of the steam cylinder 6 and controlling steam inlet ports 9, said bonnets being on the outer ends of thehousings for p the inlet valve 'st 'ans; 3 is the eccentric strap and its connecting rod through which motion is imparted from the eccentric on the governor shaft to the rock shaft 2; 5 1s the centrifugal governor mounted on shaft L and connected in the usual way to the eccentric; 8 are the bonnets for theoperating cams i of the two auxiliary exhaust valves 12, which are located at opposite ends of the steam cylinder and control the auxiliary exhaust ports 11, said cams being mounted upon and revolving with a tubular of April 22nd1913z 13 are the main exhaust ports and passages located centrally between the end of the steam cylinder and controlled with the horizontal axis of the cylinder and the auxiliary exhaust valves are located and move infthe horizontal plane offthat axis,

"as indicated in Figs. 1 ,and;2.; The extended portions of the governor shaft 4, on which the cams A' e mounted, passes through and gs in the bonnets 8. each cam ned in it si wn bonnet. Thetubularz lex ens en S pffthe gover or sha t passages to "the main exextension S of the governor shaft i. said. shaft in practice extending back tothe en gine crank shaft, and being driven from the same by gearing as more fully shown andv described in my Letters Patent No. 1,059,567v

on which the cams A are mounted is made separate from the governor shaft for a purpose which will be presently described, although connected therewith in such manner that thetwo will always revolve in unison.

' The two cams A are mounted on and rigidly fastened to the governor shaft tubularextension S, which as before said extends news shown in Fig. 3.

As shown in the same figure, the main governor shaft 4 enters the bonnet 8 adjoining the near or stufling box end of the steam cylinder, but stops short of its tubular extension S.

Connection between the shaft 4 and its extension S is inade through the intermediary of a stems which extends between and enters the tubular extension S, and the shaft 4 whose end" adjoining the extension S is made hollow for this purpose. The'stem e engages the shaft 4 by means of a feather key 18 fixed in the tubular end of the shaft 4, which enters a corresponding longitudinal groove in the stem e, thus forcing the stem to revolve with the shaft 4 while permitting its lengthwise movement independently of the latter; and said stem engages the tubular extension S through the intermediary of a crosspin a which extends diametrically through a cylindrical head f formed on the stem e, of such size and proportions as to fit the bore of the extension S and be slidable therein, the latter permitting an accurate bearing and guide for the thus movable stem. The ends of the cross pin 0 which project beyond the. head f, extend into and engage two symmetrically arranged and diametrically opposite slots or channels a formed in the extension S and extending lengthwise of, and in a spiral path around, the same.

In this way, and through the intermediary of the stem 6, connected as described with the rotary shaft 4 and its extension S, the two will be compelled to revolve always in unison. At the same time it is manifest that if the stem 6 be moved in one direction or the other in and lengthwise of the extension S, the cross pin f carried by said stem, by reason of the engagement of its projecting ends with the spiral slots or channels a in the extension S, will effect a partial rotation of the latter independently of and relatively to the governor shaft 4, the direction and extent of which partial rotation will be determined by the direction and extent of the lengthwise movement of the stem e, and consequently the lengthwise travel of the ends of the cross pin 0 in the spiral slots a of the extension S. Inasmuch as theauxiliary exhaust valve operatingcams are rigidly fixed on the extension S, they must necessarily partake of its'independent rotating movement relatively to the governor shaft 4; and in this way said cams are made rotatably shiftable relatively to the shaft 4, which, as before said, revolves in unison with the engine crank shaft, or, in other words, makes one revolution for each complete reciprocation of the steam piston, thus permitting the timing of their action upon the auxiliary exhaust valves, which they control, to be varied as desired relatively to the stroke of the steam piston, and to the main exhaust controlled by the latter. The extent of the rotatably shift-able movement of the cams will. of course, be determined by the pitch or degree of inclination of the spiral slots at and the extent of longitudinal travel of the cross pin 0 in said slots.

In order to thus operate the cross pin. the far end of the cross-pin stem 0, as shown in Fig. 3, has formed on it a head 6 contained in a cylindrical coupling box h which fits. and is free to both rotate and slide length wise in the tubular extension S. The cou pling box also contains the head i of a rod 2', there being interposed between the two abutting heads e', i, an antifricton washer w to take up lost motion between the two heads. The rod 11 extends out through the far bonnet 8, into a cylindrical housing 9 on that end of said bonnet, closed by a cap having a cylindrical interior in which fitsclosely a piston P, (which I shall term the cam piston to distinguish it from the steam piston), adapted to slide back and forth in said cap, as a piston does in a cylinder, and to make a similarly tight fit therein by means usually employed for that purpose, to prevent leakage from one side of the piston to the other. The end of the rod 2' is made fast to this pis ton; and, therefore. as the latter moves in and lengthwise of the cylindrical cap 7c, the cross pin 0, through the intermediary of the rod 2', coupling box w and stem 6 will be correspondingly moved in and lengthwise of the spiral slots a, thus producing a rotary shifting movement of the tubular extension S andcams A fixed thereon.

The interior of the cap is between its outer end or head and the piston P, is in communication with the main exhaust 13, through a system of piping p, a clearance space is being provided within the cap to permit such communication to be maintained, thus reproducing in the space within the cap behind the cam piston the pressure, or rather vacuum, conditions which prevail in the main exhaust passage. The pressure from without upon the cam piston is equal to atmospheric pressure; and within the housing 9 is a coiled ,counterbalancing spring we encircling the rod z and confined between an annular washer i fixed on the latter and a suitable stationary shoulder 0 within the housing 9, said spring being arranged to be compressed as the piston P isnioved outwardly by the superior atmospheric pressure, the resistance of the spring, of course, increasing with its compression. The position of the cam piston P in its cylinder, therefore, is determined by erate upon its own auxiliary exhaust valve at the proper time.

Assume that the steam piston, as is the Y practice in uniflow engines, uncovers the cen- '.main exhaust and vice versa.

i: increasing with tral main exhaust ports near the end of its expansion stroke, say! 10% before it reaches dead center, and that the spiral slots at are of such length and pitch, that when the cross pin 0 is at one end of said slots,-that end of the same where it is represented in Fig. 3the cams A will be so shifted as to open their valves say 8% before dead center, or after the piston on its expansion stroke has uncovered the central main exhaust ports; and when the pin is at the opposite end of said slots the cams will be shifted around in the opposite direction to a position in which each will open its valve 8% after dead center, or before the central main exhaust ports have been closed by the piston on its return stroke. The absolute period of time during which the auxiliary exhaust valve remains open is fixed and invariable, depending upon the form and dimensions of its operating cam, which are such that while the opening movement of the auxiliary exhaust valve always takes place while the main exhaust is open, said valve remains open until after the main exhaust has closed. The length of time it remains open after the main exhaust has closedwhich is the period of its effective opening will vary with the time of its opening relatively to that of the main exhaust, the approach of the time of that of the closing of the As, for exam: ple, if it opens 8% before dead center and the dimensions of its operating cam are such as to hold it open until 30% after dead centerthus giving compression, then if its operating cam be shifted so that the valve will open at 8% after dead center, it will close its opening to at about 85% after dead center, thus giving 15% compression.

it is designed, the compression, sayexhaust conditions.

, interior of the The initial set of th( cams is such that when the engine is operating under the maximum vacuum for which about 70%, advisable under those exhaust conditions will be obtained. The figures given are merely arbitrary and by way of illustration, although they will be found desirable for practical work.

In the position of the parts shown in Fig. 3, the campiston P is in its extreme outer position; the counterbalancing spring m consequently is fully compressed and the cross pin 0 is at the extreme outer end of the spiral slots a, which is the position occupied by the parts when there is exhaust pressure behind this piston equal to the maximum vacuum, say 28". for which we will su pose the engine to be designed, and

sary, under this vacuum, to open their auxiliary exhaust valves at about 8%' before dead center and close them at about 30% after dead center, in order to produce a compression of 70%- the desirable compression under these exhaust conditions.

The compression will of course vary with variations in exhaust conditions, with increase in exhaust pressure, the pressure on the exhaust side of the cam piston P correspondingly increases with the effect of moving the cam piston against atmospheric pressure from the other side, thus advancing the cross pin 0 in the spiral slots or channelsv a with the effect of rotatably shifting the cams A in a direction to open their auxiliary exhaust valves at a t1me more nearly approaching the time of closing the main exhaust, with consequent proportional prolongation of the effective open period of said valves, thus varying the compression toconform to the c ange in the In this way the advisable compression for varying conditions of the exhaust pressure wil 'be'automatically maintained.

It is true that only the two extreme positions of the cams-that is to say, the positions they occupy when the cross pin a is at one end or the other of the spiral slots w-can be chosen at will, while a lof their intermediate positions depend upon 'variations' in exhaust conditions between these two extremes. But none the less these inter mediate changes, place in such a wa as to maintain the desirable compression or any prevailing exhaust conditions.

In the head of the cap 70 is fitted a screw spindle is, havin an exterior hand wheel is for operating 1t, and extending into the cap in a position where its inner end may be advanced to bear against the piston P and push it along inadirection to advancethe cross pin 0 1n its slots a.

because when they do occur, take,

This hand-operated spindle is provided merely as a means to operate the cam setting devices in case the automatic arrangement from any cause should fail to work.

Having described my improvement and the best way now known to me of carrying the same into pract-it 1 effect, I state in conclusion that I do not limit myself to the structural details herein before shown and described in illustration of the invention subject of my claim, since manifestly the same can be varied in a number of particulars without departure from the spirit of the invention; but what I claim herein as new and desire to secure by Letters Patent is:

In a uniflow engine of the character described, the combination with the engine crank shaft, the steam cylinder and piston, and the steam admission, cut-off, and main exhaust instrumentalities; of auxiliary exhaust ports and controlling valves therefor; a rotary shaft independent of the steam admission and cut-oil instrumentalities and driven from and revolving in unison with the engine crank shaft; auxiliaryexhaust-valve operating cams driven from and revolving in unison with said rotary shaft, actmg to open the aumhary-exhaust valves always before the main exhaust 30 length of said efl'ective open period will vary with and depend upon the rotary adjustment of said operating cams with reference to their driving shaft, and means for automatically thus adjusting said rotatably shiftable cams conformably to variations in the exhaust pressure.

In testimony whereof I afiix my signature.

SIEGFRIED ROSENZWEIG. 

